Strip perforating apparatus

ABSTRACT

An apparatus for continuously perforating strip material, i.e. for applying the sprocket perforations along the edge of a film strip. To achieve uniform spacing of these perforations, a work station is established in relation to a rotating circumferential arrangement of punch or perforating devices wherein each punch, in turn, is projected through the strip to cause said perforation. Said punch is held in its projected position through the strip during its subsequent rotative traverse, thereby pulling a selected length of the strip through the work station and locating accurately the next point on the strip where the next perforation is to be made.

United States Patent Borello July 15, 1975 STRIP PERFORATING APPARATUS Primarv Eraminer-Frank T. Yost l t:D B ll,l42N'kA., [76] men or gggxf gf {6 ydc Ve Attorney, Agent, or FrrmBauer & Amer [22] Filed: Apr. 4, 1974 57 ABSTRACT [211 Appl. No.: 457,782 An apparatus for continuously perforating strip material, i.e. for applying the sprocket perforations along the edge of a film strip. To achieve uniform spacing of 2% r3; these perforations, a work station is established in rei "i 322 lation to a rotating circumferential arrangement of 0 can: punch or perforating devices wherein each punch, in

turn, is projected through the strip to cause said perfo- [56] References cued ration. Said punch is held in its projected position UNITED STATES PATENTS through the strip during its subsequent rotative tral,559,987 11/1925 Reinhardt 83/337 verse, thereby pulling a selected length of the strip 1,910,395 5/l933 Kreis v. 83/337 X through the work station and locating accurately the 2983-370 6/1937 Greuhch 3 v 33/337 next point on the strip where the next perforation is to 2,760,576 8/l956 Spencer 83/337 X be made 2,963,932 l2/l960 Glueck t r 83/337 3,661,044 5/1972 Duden et al. 83/337 X 1 Claim, 4 Drawing Figures 1 l f "Z3 52 I 40 50 .1 42 26\ D" l 46 IO 32 24) 38 STRIP PERFORATING APPARATUS The present invention relates generally to perforating apparatus, and more particularly to improved apparatus for accurately providing perforations at uniform spacing along an elongated plastic strip. An exemplary product produced by the within apparatus is a film strip with marginal edge feed movement sprocket openings or perforations that are precisely located so as to provide the desired meshing engagement with the teeth of the sprocket.

The prior art practice of producing a series of perforations along a plastic strip contemplates the simultaneous production of perhaps ten perforations, all uniformly spaced from each other, and then the movement of an adjacent length portion of the strip into the perforating or work station. While, as noted, each group of ten perforations are uniformly spaced, the spacing between adjacent groups may not be as precise as is required. The accuracy thereof would be a function of the accuracy of the mechanism feeding the strip into and out of the work station. Also, the technique described contemplates incremental, rather than a continuous and smooth, feed movement in the strip, and thus is undesirably slow, as well as being subject to malfunctioning in the strip-handling mechanisms that must be employed to provide this incremental movement.

Broadly, it is an object of the present invention to provide a rotary perforating apparatus, characterized by continuous, efficient perforating operation, overcoming the foregoing and other shortcomings of the prior art. Specifically, it is an object to achieve uniform spacing of perforations as a function of the uniform spacing of punch devices producing said perforations, and to further achieve a continuous mode of operation in the apparatus by a circumferential arrangement of said punch devices.

An apparatus demonstrating objects and advantages of the present invention includes a circumferential arrangement of punches, all normally in a raised or ready position, and means in the rotary path of said punches for camming each, in turn, through a stroke producing a perforation. Additional means maintain the punch in its projected condition through the strip so that the rotational traverse thereof pulls the adjacent area of the strip into the work station incident to the application in this area, at a precisly located point, of the next perforation.

The above brief description, as well as further objects, features and advantages of the present invention, will be more fully appreciated by reference to the following detailed description of a presently preferred, but nonetheless illustrative embodiment in accordance with the present invention, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a strip perforating apparatus demonstrating objects and advantages of the present invention;

FIG. 2 is a partial side elevational view, in section, illustrating further structural features of the apparatus;

FIG. 3 is a partial front view, taken along lines 33 of FIG. 2, illustrating additional structural features; and

FIG. 4 illustrates a perforated strip that is produced by the apparatus hereof.

Illustrated in FIG. 4 is a typical film strip having sprocket perforations 12 along a marginal edge [4. Proper movement of the film strip 10 by the feeding sprocket gear of the projector, camera, etc., require a uniform spacing 16 between the perforations [2, as well as accurate uniform sizes in each of the perforations 12. The foregoing and other desirable criteria are readily achieved by the strip perforating apparatus, generally designated 20, which constitutes the present invention.

As illustrated in FIGS. 1-3, apparatus 20 includes a stationary housing having an upstanding member 22 in which shaft 24 is appropriately journalled for rotation, as at 26. One extending end of shaft 24 is driven in rotation by a pulley connection 28 to a motor. At its other end, as best illustrated in FIG. 2, shaft 24 has connected to it, as by bolt 30, a conical rotor 32, the function of which will soon be apparent. It suffices at this point to note that the conical or cone rotor 32 rotates in unison with shaft 24.

Also rotating in unison with shaft 24 is a housing 34 which is bolted as by bolts 36, 38, so as to constitute an attachment to the construction consisting of the shaft 24 and cone rotor 32. An important part of the housing 34 is a ring-like segment 40 which is bolted by circumferentially spaced bolts 42 in overhanging relation to an inwardly located portion 44 of the cone rotor 32. As a consequence, the rotor portion 44 and the segment 40 bound a cylindrical punch compartment 46. In other words, as is best illustrated in FIGS. 1 and 3, the punch compartment 46 is in the nature of a cylindrically shaped clearance which exists between the rotor end 44 and the housing segment 40 which overhangs said rotor end 44.

In addition to segment 40, housing 34 includes an outer segment 48. As is best illustrated in FIG. 2, the segments 40 and 48 cooperate to provide a housing structure for a plurality of radially oriented openings, each consisting of a through bore 50 and a counter bore 52. Disposed for vertically reciprocating movement in the interconnected bores 50, S2 is a punch device 54, having a bottom perforating tip 56. At its opposite end, the punch device 54 has a threadably engaged cam block 58. In practice, block 58 is engaged by a rotary cam member 60 with the result that each punch device 54, in turn, is projected from a raised ready position through a punching stroke, during which its perforating tip 56 is urged through the strip 10 into the projected position shown in FIG. 2. This, of course, produces a perforation 12 in the strip 10. The aforesaid punching stroke of each punch device 54 is produced against the urgency of a helical spring 62 which normally holds the same in its raised, ready position. The depth of the punching stroke is adjusted by threaded adjustment of a collar 54 on the upper end of each punch device 54.

The significance, in terms of function, of the foregoing can perhaps best be appreciated by reference to FIGS. 2, 3. As illustrated therein, the noted camming means 60 consists of a cylinder rotatably mounted to extend from block 65 transversely of the circumferential path of rotation of the housing 34, and thus of the punch device 54 circumferentially located about the housing 34. As a consequence, each punch device 54, in turn, during counter-clockwise rotation of the housing 34 must contact the camming cylinder 60. This contact between the cylinder 60 and the cam block 58 of each punch device results in each said punch device, in turn, being depressed from its raised, ready position to its forwardly projected position in which it is projected through the body of the strip l and produces the perforation 12 in the marginal edge 14 thereof. In FIG. 3 this punch stroke which is caused sequentially by the circumferentially arranged punches 54 can best be understood by noting the punch identified as 54A which is already under the camming influence of cam 60 and the next punch to encounter said cam 60 which is identified by the designation 543.

In addition to actual production of the perforation 12, it is an important aspect of the present invention that the punch devices 54 also provide feed movement of the strip into and through the punch compartment 46. To this end, situated adjacent the first cam cylinder 60 is a second encountered cam cylinder 66. The function of cylinder 66 is to maintain the punch which is in its projected position through the strip 10, as just described, in said projected position during the rotative traverse of the housing 34 from cam cylinder 60 and until the punch cam block 58 clears said second encountered cylinder 66.

The foregoing may be better understood from FIG. 3 by noting how the depressed or projected position of punch 54A, which is created by the first encountered cam 60, is preserved by the second encountered cam 66 in the punch designated 54C. Thus, during the rotative traverse 68, the perforating end 56 of a punch device is projected through a perforation 12 in the strip 10 and thus carries the strip along with it causing a feed movement 70 in the strip.

The manner in which the strip 10 is properly located in the punch compartment 46 in position to be perforated by the circumferentially arranged punch devices 54 may best be understood from FIGS. 1 and 2. Rotor 32 is conically shaped so that, as illustrated in FIG. 1, strip 10 is unwound from a supply spool 72 or the like and is threaded within the compartment 46, as illustrated in FIG. 2, for only for a portion, but not for an entire, rotational traverse of the cone rotor 32 and housing 34. Assisting in guiding strip 10 through this path is an initial guide roller 74 oriented at approximately the same angle as the upper angular surface of cone rotor 32 as illustrated in its FIG. 2 position of rotation. At the exit side of compartment 46 there is a similarly angularly oriented roller 76. Rollers 74 and 76 extend from the vertical mounting block 78. Proper tracking of the strip 10 is also assisted by a take-up spool (not shown) which applies a slight tensioning force 80 to the perforated length portion of the strip exiting from the punch compartment 46.

The material perforated out of the body of the strip 10 is collected in the hollow interior of the cone rotor 32 which is appropriately designed that said collected material passes out of it by the rotating action of the unit.

It should be readily appreciated that there has been described herein an apparatus 20 for continuously producing perforations 12 in the marginal edge 14 of an elongated strip 10. This continuous mode of operation is noteworthy in that it assures uniform spacing 16 between adjacent perforations 12. That is, any selected uniform spacing 16 which is desired between adjacent perforations 12 is readily achieved merely by proper circumferential uniform spacing of the punch devices 54 about the housing 34. This is illustrated in FIG. 3 wherein by proper selection of a uniform angle 82 subtended by adjacent punch devices 54 there will be a corresponding uniform spacing in the adjacently produced perforations 12.

A latitude of modification, change and substitution is intended in the foregoing disclosure and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.

What is claimed is:

1. A strip perforating apparatus comprising a motor operated conically shaped rotor, an overhanging housing on said rotor bounding a cylindrical punch compartment in surrounding relation about said rotor, plural punch devices circumferentially arranged about said housing and means for mounting each for movement through a punch stroke from a ready position into said punch compartment to a projected position, a cooperating spring for each punch device which normally holds the same in said ready position, a first encountered rotatably mounted cylindrically shaped cam strategically located in the path of rotative movement of said punch devices effective to urge each punch in turn through said punching stroke, means for positioning a length portion of an elongated strip in said punch compartment so as to be perforated by each said punch during its movement into said projected position, and a second encountered rotatably mounted cam adjacent said first cam effective to hold each punch in turn in said projected position in which it extends through a perforation in said strip during rotative movement from said first cam and until past said second cam, whereby each punch in turn causes a perforation in said strip and also pulls the same in feed movement through said punch compartment. 

1. A strip perforating apparatus comprising a motor operated conicAlly shaped rotor, an overhanging housing on said rotor bounding a cylindrical punch compartment in surrounding relation about said rotor, plural punch devices circumferentially arranged about said housing and means for mounting each for movement through a punch stroke from a ready position into said punch compartment to a projected position, a cooperating spring for each punch device which normally holds the same in said ready position, a first encountered rotatably mounted cylindrically shaped cam strategically located in the path of rotative movement of said punch devices effective to urge each punch in turn through said punching stroke, means for positioning a length portion of an elongated strip in said punch compartment so as to be perforated by each said punch during its movement into said projected position, and a second encountered rotatably mounted cam adjacent said first cam effective to hold each punch in turn in said projected position in which it extends through a perforation in said strip during rotative movement from said first cam and until past said second cam, whereby each punch in turn causes a perforation in said strip and also pulls the same in feed movement through said punch compartment. 